From Boston to Boca, and everywhere in between, the cool-off fitness fad of the heat and humidity-crazed may be flo-yo — that's floating yoga to the uninitiated. Insane as it sounds, stand up paddleboard (or SUP, as devotees call it) yoga classes is a new water workout trend that's taking off, fusing two beloved forms of fitness: stand up paddleboarding and yoga. (Jennifer Aniston is a supposed fan.)

Classes, which range from $25-40 a pop, consist of a yoga instructor and a handful of students paddling out anywhere from 10 to 30 minutes and tucking into an inlet, cove or key — any calm, glassy-watered spot for 30 to 60 minutes of yoga moves on the 11 1/2-feet long, 29-inch wide paddleboard.

“We start as you would any traditional yoga class and open with chanting and some breathing practices, and then warm up with standing postures and lunges,” says Tara McCabe, owner of Key West Stand Up Paddle Board Yoga. McCabe’s class runs two hours — 30 minutes of paddling each way with an hour of yoga.

Tara McCabe

Anisa Butash does the camel pose during a class with the Key West Stand Up Paddle Board Yoga in Key West, Fla.

She uses 10-pound mushroom anchors that clip onto the back of the boards and ground the yogis in shallow water three or four feet deep, usually in a Key West mangrove. Mother Nature isn’t usually an issue since selected spots are out of the wind and current to enhance the focus on balance.

“The biggest thing is getting over the fear and letting go and knowing that the board is specifically designed to stand up on,” says McCabe.

Scotty Bumbalough, owner of Maui B in Orlando, Daytona and Coco Beach, says classes are for all skill sets but do require some balance. Flo-yo develops a sense of focus, core strength and improves your stabilizer muscles. Practicing yoga on a floating mat where fish, sea turtles, waterfowl and depending on where you live heavy hitters like manatees or harbor seals swim by, is nothing short of a Zen workout, too.

“I would not replace it with a studio practice but I think it compliments a studio practice,” says McCabe. In fact, experienced yogis master floating headstands and crow pose. Newbies modify poses to their skill level. Add paddling in and out is both meditative and a total body workout.

Oh, and if you fall in, it’s no biggie. Besides, the water feels good and everyone laughs it off, since it does happen occasionally.